Department of Cardiac Diagnostics, Medical University of Gdansk, Poland.
Department of Biochemistry, Medical University of Gdansk, Poland.
Microvasc Res. 2025 Jan;157:104748. doi: 10.1016/j.mvr.2024.104748. Epub 2024 Sep 16.
Long COVID is a complex pathophysiological condition. However, accumulating data suggests that COVID-19 is a systemic microvascular endothelial dysfunction with different clinical manifestations. In this study, a microvascular function was assessed in long COVID patients (n = 33) and healthy controls (n = 30) using flow-mediated skin fluorescence technique (FMSF), based on measurements of nicotinamide adenine dinucleotide fluorescence intensity during brachial artery occlusion (ischemic response, IR) and immediately after occlusion (hyperemic response, HR). Microcirculatory function readings were taken twice, 3 months apart. In addition, we quantified biochemical markers such as the serum L-arginine derivatives and hypoxia-inducible factor 1α (HIF1α) to assess their relation with microvascular parameters evaluated in vivo. In patients with long COVID, serum HIF1α was significantly correlated to IR (r = -0.375, p < 0.05). Similarly, there was a significant inverse correlation of serum asymmetric dimethyl-L-arginine levels to both HR (r = -0.343, p < 0.05) and HR (r = -0.335, p < 0.05). The IR parameters were found lower or negative in long COVID patients and recovered in three-month follow-up. Hypoxia sensitivity value was significantly higher in long COVID patients examined after three months of treatment based on the combination of ACE-inhibitors and beta-adrenolytic compared to baseline condition (85.2 ± 73.8 vs. 39.9 ± 51.7 respectively, p = 0.009). This study provides evidence that FMSF is a sensitive, non-invasive technique to track changes in microvascular function that was impaired in long COVID and recovered after 3 months, especially in patients receiving a cardioprotective therapy.
长新冠是一种复杂的病理生理状况。然而，越来越多的数据表明，新冠病毒感染是一种全身性的微血管内皮功能障碍，具有不同的临床表现。在这项研究中，我们使用血流介导的皮肤荧光技术（FMSF）评估了长新冠患者（n=33）和健康对照组（n=30）的微血管功能，该技术基于测量肱动脉闭塞（缺血反应，IR）期间和闭塞后即刻（充血反应，HR）烟酰胺腺嘌呤二核苷酸荧光强度。微血管功能读数每 3 个月测量一次，共测量两次。此外，我们还量化了血清 L-精氨酸衍生物和缺氧诱导因子 1α（HIF1α）等生化标志物，以评估它们与体内评估的微血管参数的关系。在长新冠患者中，血清 HIF1α 与 IR 呈显著负相关（r=-0.375，p<0.05）。同样，血清不对称二甲基-L-精氨酸水平与 HR 呈显著负相关（r=-0.343，p<0.05）和 HR 呈显著负相关（r=-0.335，p<0.05）。IR 参数在长新冠患者中较低或为负值，并在 3 个月随访中恢复。经过 3 个月的 ACE 抑制剂和β受体阻滞剂联合治疗后，长新冠患者的缺氧敏感性值明显高于基线（分别为 85.2±73.8 和 39.9±51.7，p=0.009）。这项研究提供了证据表明，FMSF 是一种敏感的、非侵入性的技术，可以跟踪长新冠患者受损的微血管功能变化，这些变化在 3 个月后得到恢复，尤其是在接受心脏保护治疗的患者中。
